Delayed complication of tracheocutaneous fistula closure with severe compromising subcutaneous emphysema

Abstract

We report a significant complication after tracheocutaneous fistula (TCF) excision with closure by secondary intention in a 4-year-old boy who had been tracheostomy dependent since infancy. He had a persistent 3 mm TCF one year after decannulation. On postoperative day 2 the patient developed profound subcutaneous emphysema and pneumomediastinum. He was extubated after 2 days and discharged from the hospital on postoperative day 7. At follow up he had complete resolution of subcutaneous emphysema and complete closure of the TCF. The main methods of TCF closure and management of subcutaneous emphysema are discussed along with the lessons learned from this case.

Background

Tracheostomy is a common paediatric surgery. Many patients that need a tracheostomy can eventually be decannulated. A tracheocutaneous fistula (TCF) develops when the stoma fails to close spontaneously after decannulation. Patients who require tracheal cannulation for over 12 months are especially susceptible to developing a TCF.¹ TCFs have a wide reporting incidence of anywhere from 6% to 55% of paediatric tracheostomy cases and can lead to respiratory infections, chronic cough and difficulty with phonation.^{2 3} Persistent TCFs are indicated for surgical closure after a 3–6-month period of conservative management.⁴ We report a rare case of delayed severe subcutaneous emphysema after TCF excision with closure by secondary intention.

Case presentation

A 4-year-old boy with a history of tracheostomy dependence since infancy due to restrictive lung disease secondary to a giant omphalocele, underwent uneventful decannulation at age 3. One year after decannulation he had a persistent 3 mm TCF. The TCF continued to have intermittent drainage and the family desired to undergo surgery to close the TCF. Due to the concern for A-frame stenosis, he was scheduled for excision of TCF with anterior tracheoplasty using thyroid alar cartilage.

At the time of surgery, no tracheal stenosis was appreciated, so the decision was made to excise the TCF and allow to close by secondary intension. This was done by creating an ellipse on the skin and following the tract down to the cartilaginous trachea to completely excise the tract. A 2.5 peds tracheostomy tube was placed in the opening and the skin was partially closed around the tracheostomy tube. He was then decannulated and a non-occlusive dressing was placed over the incision once awake in the paediatric intensive care unit (PICU). Overnight he did not have any issues and on postoperative day 1 the skin appeared closed without any drainage. Plans were made to discharge home with only antibiotic ointment dressing. However, he started getting agitated, crying and breath holding when the dressing was removed, and it was noted that he started having some mild swelling with crepitus around the incision consistent with subcutaneous emphysema. The swelling appeared to be stable at that time.

Treatment

As the subcutaneous emphysema was mild and seemed stable, an occlusive pressure dressing was placed over the incision in attempt to prevent any further leaking from the tracheal defect. He was kept in the hospital for further observation. Overnight on postoperative day 2, he became more agitated with increased pain, crying and vomiting. It was then noted that he developed a rapid progression of profound subcutaneous emphysema involving the face, neck, arms and chest (figure 1A). He was urgently transferred to the PICU and subsequently intubated. Intubation showed subcutaneous emphysema involving the vallecula leading to a challenging but uneventful endotracheal intubation. Care was taken to make sure that the endotracheal tube cuff was placed distal to the fistula opening in the trachea. After intubation a chest X-ray showed profound subcutaneous emphysema and pneumomediastinum (figure 1B). The following day (postoperative day 3) the endotracheal tube cuff was deflated, and the skin incision probed open to appreciate a free leak coming from the incision. A passive drain was placed to keep the skin open.

Figure 1.

Postoperative day 2 (A) patient immediately before intubation and (B) chest X-ray after intubation showing known dextrocardia and severe subcutaneous emphysema and pneumomediastinum.

Outcome and follow-up

The subcutaneous emphysema improved and on postoperative day 4 he was able to be extubated as soon as the airway was determined to be stable (figure 2). The subcutaneous emphysema continued to improve, and the drain was removed. He was later discharged from the hospital on postoperative day 7. He had no concerns at home, and at his follow-up appointment the subcutaneous emphysema was completely resolved (figure 3). His skin incision was well healed without any signs of persistent TCF.

Figure 2.

Postoperative day 4 after extubation.

Figure 3.

Anteroposterior and lateral neck films 2 weeks postop showing resolution of subcutaneous emphysema. R stands for Right side of the AP film. PGR are the initials of the Radiology technician.

Discussion

Various methods of surgical closure of a TCF have been described. The most common closures performed are primary layered closure and closure by secondary intention. An anterior laryngotracheoplasty also can be done for a large TCF, or if at the time of TCF closure the patient is found to have tracheal stenosis.⁵ For this reason it is recommended that a direct laryngoscopy and bronchoscopy is done at the time of surgical closure of any TCF.⁶

Primary layered closure of a TCF entails removing the TCF tract down to trachea and then closing in 3 or 4 layers: (1)+/− closure of tracheal defect, (2) mobilise and close anterior infrahyoid muscles over the tracheal defect, (3) subcutaneous fat and (4) skin.^{4 7–9} A small rubber band drain is often placed at the time of closure to reduce the risk of subcutaneous emphysema. Primary closure has the main advantage of a definitive closure and improved cosmetic outcome.^{8 9} Due to the risks of subcutaneous emphysema from closing the skin, patients are usually monitored for a day in the PICU.^{10 11}

Closure by secondary intention, as described in this case, involves excision of the fistula similar to primary closure. But instead of a layered closure, a small tracheostomy tube is placed. This is then removed once the patient is awake. Often these patients can be monitored in the postanaesthesia care unit and discharged home the same day if stable, or they can be observed overnight on a routine hospital floor.¹⁰ Closure by secondary intension has the risk of more scarring with healing as well as formation of a persistent TCF.⁴

Anterior laryngotracheoplasty, also referred to as a cartilage cap graft, is used for those with known tracheal stenosis or large tracheal defects where a primary closure would cause A-frame stenosis.¹² Like other closures, the fistula tract is excised and then a cartilage graft is sutured into the anterior tracheal wall to repair the tracheal defect. Various cartilage donor sites can be used such as the ear, thyroid ala or rib.^{6 12 13} Skin is then closed primarily. A stent is usually kept in the airway and hospital stays are much longer when compared with primary closure or closure by secondary intention. The three distinct methods of TCF repair and their associated benefits and risks are described (table 1).

Table 1.

Methods of tracheocutaneous fistula repair

Methods of repair	Description	Benefits	Risks
Primary closure	Elliptical skin excision with fistulectomy. Three or four-layered closure of tracheal defect, infrahyoid muscles, subcutaneous fat and skin. Placement of rubber band drain between strap muscles.	Improved cosmetic outcome. Definitive closure. Lower risk of forming persistent fistula.	Subcutaneous emphysema, pneumothorax, pneumomediastinum, respiratory distress and hypoxia. Scarring of strap muscles if not carefully mobilised. A-frame tracheal stenosis especially with larger tracheal defects. Longer operative time and longer observation needed compared with secondary intention.
Closure by secondary intention	Elliptical skin excision with fistulectomy. No creation of skin or muscle flaps. Recannulation with smaller, uncuffed tracheostomy tube. Decannulation when awake and allow incision to heal by secondary intension.	Shorter operative times. Shorter observation periods.	Subcutaneous emphysema, pneumothorax, pneumomediastinum, respiratory distress and hypoxia. Failed spontaneous closure may produce a persistent TCF. More likely to produce unsightly scarring. A-frame tracheal stenosis.
Cartilage graft laryngotracheoplasty	Elliptical skin excision with fistulectomy. Cartilage harvested and grafted onto anterior wall of trachea at site of TCF. Closure in standard, layered fashion. Placement of stent and rubber band drain.	Prevents A-frame tracheal stenosis when TCF>5 mm. Widens airway if tracheal stenosis already present.	Subcutaneous emphysema, pneumothorax, pneumomediastinum, respiratory distress and hypoxia. Cartilage harvest and donor sight complications. Longer observation and additional procedures needed for stent removal and evaluation of graft uptake. Failure of graft uptake.

The development of subcutaneous emphysema, pneumomedastinum or pneumothorax is some of the major feared complications that can occur with any method of TCF closure.¹⁴ There have been reports of severe subcutaneous emphysema anywhere from immediately postoperative to 7 days out.^{8 14} These delayed cases were reported in patients that had a TCF repair with primary closure. This case highlights the unusual delayed development of subcutaneous emphysema with closure by secondary intention. Severe complications were thought to occur more frequently in primary closure. However, recent systematic reviews have reported that management of TCFs with primary closure or closure by secondary intention are similar in effectiveness and in incidence of minor and major operative complications.^{9 15}

In this case on postoperative day 1 the skin had already closed enough to trap the escaping air from the tracheal defect when there was increase tracheal pressure from crying. To prevent further leaking of air from the tracheal defect, a pressure dressing was attempted. However, this seemed to exacerbate the problem due to discomfort. It is also ensured that no air could escape from the incision. It is possible that this complication could have been avoided if at the time of first noticing subcutaneous emphysema the incision had been probed open and a passive drain was placed in the incision instead of placing an occlusive dressing.

To protect an unstable airway this patient was intubated. However, subcutaneous emphysema and pneumomediastinum usually are managed with supportive treatment and correction or repair of the area responsible for leaking air.¹⁶ The trapped air is resorbed spontaneously by the body over time. Supportive treatment consists of observation, reassurance, rest, control of pain and supplemental oxygen.¹⁷ Aqhajanzadeh et al described a 1–5 severity grading system for classifying subcutaneous emphysema, with 5 being the most severe involving face, chest, arms, abdomen and scrotum/labia. They discussed that usually only level or severe subcutaneous emphysema that becomes intolerable to the patient, or interferes with breathing, needed surgical intervention to prevent complications of tension pneumomediastinum and pneumothorax. Interventions they described were based on locations of trapped air such as chest tube, subcutaneous catheters or blow hole incisions.¹⁷ In this case the patient had what would be classified as grade 5 or massive subcutaneous emphysema. Due to the pain, vomiting and rapid progression of subcutaneous emphysema he met indications to intervene with intubation. This not only protected his airway but also occluded the source of the air leak. Opening the incision and keeping it open acted like a blow hole incision to provide another path for air to escape. Once assured that the subcutaneous emphysema was improving, and the patient could maintain a safe airway, he was extubated. He was then treated conservatively until the subcutaneous emphysema resolved completely.

Learning points.

• Severe subcutaneous emphysema can be delayed and can occur even in tracheocutaneous fistula (TCF) closure by secondary intention.

• We recommend against using pressure dressings or occlusive dressings in the closure of a TCF as these may exacerbate the problem resulting in a rapid progression of subcutaneous emphysema.

• If subcutaneous emphysema starts to develop, insure that the incision is open and remains open with a passive drain and treat as conservatively as possible with observation, supplemental oxygen, and pain management.

• If the airway is at risk, then intubation is indicated but insure that a cuffed endotracheal tube is used and inflated below the TCF so as not to continue pushing air into the subcutaneous tissues. Extubate as soon as possible to prevent further complications.